Thanks for the ideas, I did get this working. Apparently yabause has removed command line support for loading as of the last few versions.
The emulator can be setup however so that it always loads the same file. Because the Saturn CD images are stored as .cue and .bin files, I was able to find a workaround.
Setup yabause to always load "default.cue" , then set MaLa to look for the .cue files. Add small script to copy the selected .cue file as "default.cue", and added that as a pre-command to run before launcing the emulator.
MaLa command was: G\Saturn\preload.bat "%path%\%rom%%ext%", .bat command was: copy %1 G:\Saturn\defalt.cue /y